Garrett, who was one of a team of experts brought in to authenticate the coin in 2003, said he'd been excited about the coin ever since he first handled it.

"We've both always dreamed about owning these coins," he said. "This is probably the greatest coin I've ever handled."

While five Liberty Head nickels are currently known to exist, the story of this particular coin added a new dimension to its allure for Lee and Garrett.

The coin's former owner, George Walton, died in a car accident in 1962. His family recovered the nickel from the car wreck but was told that the coin was counterfeit. Walton's sister kept the coin anyway, stowing it away in a closet with the label "It's not real."

Walton's sister's four children inherited the coin and brought it to auction this year, after learning more about its authenticity at the 2003 American Numismatic Association World's Fair of Money in Baltimore.

Attempts by ABC News to contact the heirs were not successful, but Cheryl Myers, one of the four heirs, told the the Associated Press, "The sad part is my mother had it for 30 years and she didn't know it."

Decades later, Lee said he couldn't believe he owned the now authenticated coin, and that he got it at such a great price. "The coin at that value is severely undervalued. I was willing to pay $4 million.

"This coin has been rare forever. This is like the holy grail of the coin business."

Lee said the coin would be on display next month in New Orleans at a American Numismatic Association exhibition, where he wants as much of the public to see it as possible.

But he doesn't have any other future plans for the coin. "I just wanted to own that coin," he said.